A device for generating electrical energy from the heat dissipated by a heat source, comprising: a capacitor comprising two electrodes between which a ferroelectric material is present, said capacitor being arranged so as to be positioned to capture all or part of the heat dissipated by said heat source; a capacitive element a first electrode of which is connected to a first electrode of said capacitor; a recovery circuit interposed between the second electrode of said capacitor and the second electrode of the capacitive element, and able to have the current flowing between said second electrodes pass through it. a mechanism adapted to move the capacitor with respect to the heat source, said mechanism having at least one arm able to move between two positions, the capacitor being closer to the heat source in one of the two positions.